docs: def contains_plural_field(model, fields):
      """ Returns a boolean indicating if ``fields`` contains a relationship to multiple items. """
      source_model = model
      for orm_path in fields:
          model = source_model
          bits = orm_path.lstrip('+-').split('__')
          for bit in bits[:-1]:
              field = model._meta.get_field(bit)
              if field.many_to_many or field.one_to_many:
                  return True
              model = get_model_at_related_field(model, bit)
      return False